Can't launch to Firefox for HTML testing. (4.16)

I can’t seem to find a way to successfully test launch a HTML scene in 4.16 and the options to launch in Firefox (Or any browser) is missing. I also decided to try 4.15 and the options are present. The image below also shows the result if I try to package the project within the launcher.

Fire Fox Nightly? I remember you needing that to run it

be sure that you have the correct evn var for EMSCRIPTEN


C:\Program Files\Epic Games\UE_4.16\Engine\Extras\ThirdPartyNotUE\emsdk\emscripten\1.37.9

it fixed the issue for me.

Hey, so I’ve been working from MAC (Idk if that’s at all relevant) and I have absolutely NO idea how to set an environment variable for EMSCRIPTEN. Any tips?